1. Field of the Invention
This invention relates to heat treating water, and more specifically this invention relates to a device and method for heat-treating water via direct contact heating.
2. Background of the Invention
Water reclamation is rapidly becoming a priority for users of high amounts of water. Such users include industrial chemical users, and food processors, the later of which often require liberal rinses of water to wash fruits, vegetables and animal carcasses. Other high water uses include sewage disposal.
Systems exist to extract volatile chemicals from water. U.S. Pat. No. 5,176,798 to Rodden on Jan. 5, 1993 discloses a system for removing and reclaiming volatile organic contaminants from water. U.S. Pat. No. 6,103,191 discloses a system for pasteurizing and dewatering sludge.
Other significant pollutants are pathogens. Pathogens are of particular concern in food processing operations, as outlined supra. As such, before water can be discharged, some jurisdictions require that pathogen levels be decreased. Furthermore, instead of direct discharge into the environment, reuse of water may be in order, particularly in areas prone to water shortages.
In light of the foregoing, methods and technologies that reduce water consumption or allow for water recycling and reclamation are becoming more appealing to many food processors. For example, a process exists (U.S. Pat. No. 3,962,076) for converting aqueous sewage to potable water. However, that process relies on “coking” sewage to form gases, coke and effluent.
Another water treatment method (disclosed in U.S. Pat. No. 3,986,955) relies on subjecting waste water to an electric current to produce water vapor.
Other water treatment methods utilize heat. For example, U.S. Pat. No. 5,487,814 utilizes multiple columns for distilling and sterilizing feed water.
A need exists in the art for a water reclamation treatment method which employs a single step, and high efficiency heat exchange. The method should be applicable to existing water heating systems, and facilitate the minimization of both liquid and vapor phase pathogen-laden effluents.